This invention relates generally to a packaging machine for use in stores, such as supermarkets and the like, and more particularly to a machine that forms individual bags from a continuous roll of tubular packaging material and seals the tops of the bags after they have been filled with goods.
In large self-service retail stores, the ordinary practice is to package purchased goods in paper bags after the price has been tabulated at the check-out counter. The empty bags are usually folded into flat form for convenient storage, and the time required to manually unfold the bags in order to fill them with goods delays the packaging operation and contributes greatly to the bottlenecks that often build up at check-out counters. Since the filled paper bags are not sealed at the tip, they must be carefully filled and handled to prevent their overturning and the contents from spilling. Furthermore, paper bags are susceptible to tearing and frequently fail under the weight of heavy goods, particularly if a liquid container carried within a bag should leak. Also, the packaging of goods in paper bags has created security problems because of the ease with which stolen items can be deposited and concealed in the open bags.
The present invention overcomes all of these problems by providing a machine that automatically forms successive bags held open at the top by a blower. After a bag has been filled with objects, the top of the bag is sealed and the next succeeding bag is immediately formed and advanced into position for receiving additional goods. Consequently, the time lag between the filling of successive bags is minimal and the packaging operation can be carried on continuously. Moreover, since the bags are formed of a strudy synthetic material and are sealed at the top, security problems and the possibility of the bags tearing or the contents spilling is virtually eliminated.
An object of the invention is to provide a method and apparatus for successively forming sturdy bags with openings in their top portions for receiving objects, and for sealing the tops of the bags after they have been filled with objects.
In conjunction with the preceding object, it is an additional object of the invention to provide a method and apparatus for packaging goods in leakproof, transparent bags. The packaging material preferably used with the invention is characterized by strength to prevent the bags from tearing or leading, while the transparency of the bags permits packaging techniques to be monitored and deters shoplifting. Also, since the packaging material requires less storage area than paper bags, available space is more efficiently utilized.
Another object of the invention is to provide, in an apparatus of the character described, means for holding the top portion of the bag open as objects are being inserted thereinto.
Yet another object of the invention is to provide an apparatus of the character described wherein the top of one bag is sealed and the next succeeding bag is formed and immediately advanced into a convenient position for receiving goods.
Still another object of the invention is to provide an apparatus of the character described which effects a weakened perforation line if desired near the top seal to facilitate the opening of the filled bag. An optional perforating blade may be included to accomplish this feature.
A further object of the invention is to provide, in an apparatus of the character described, a single member operable to seal and perforate the top of one bag, while simultaneously sealing the bottom of the next succeeding bag and severing the packaging material between the two seals.
A still further object of the invention is to provide an apparatus of the character described in which a single motor drives all of the working components. This feature is achieved by providing a lost motion connection as part of the linkage between the motor and the advance means, assuring that the bag forming members are withdrawn from engagement with the packaging material prior to the advancement thereof.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.